Characterization of new starches separated from several traditional Chinese medicines

Starches were isolated from three traditional Chinese medicines (TCMs), Angelica dahurica (AD), Trichosanthes kirilowii (TK) and Polygonum multiflorum (PM), which were investigated for amylose content, morphological, thermal, crystal, swelling factor, and pasting properties. Amylose contents of AD, TK and PM were 20.8%, 30.3% and 31.8%, respectively. The granule lengths were in the size of 5–30 μm, 10–22.5 μm and 8.7–18.7 μm, respectively. The decomposition temperatures were similar at about 325 °C. The AD and PM starches showed the typical B-type, while TK starch was the C-type. The degrees of crystallinity for AD, PM and TK were 38.33%, 43.10% and 36.71%. In differential scanning calorimetry analysis of starches, the transition temperatures, transition range, and enthalpies of gelatinization (ΔHgel) were determined. The pasting properties were also analyzed by using a Rapid Visco Analyzer. The dependence of swelling factor for three starches on temperature was tested at 10 °C intervals between 50 °C and 90 °C.